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随着人类社会工业化进程的推进, 化石能源被过度消耗, 人类向大气中排放过量的二氧化碳, 造成能源危机和环境问题. 通过电催化二氧化碳还原反应来制备高附加值精细化学品是积极探索建立人工碳循环的方向之一, 引起了基础研究与工业应用领域研究者的广泛关注. 设计与制备具有高活性、高选择性和高稳定性的电催化剂对于实现二氧化碳高效还原具有重要意义. 近年来, 关于催化剂与电极材料的结构设计和应用案例有许多报道, 取得了显著的进步. 分别从尺寸效应、表面特性、缺陷工程和多级结构四个方面对催化剂结构与电极结构的调控策略进行了综述, 并对电催化二氧化碳还原领域的发展进行了展望. 相似文献
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二氧化碳电还原技术可以将可再生电能与温室气体二氧化碳转化为高价值燃料和化学品.选择性、能量转化效率、碳利用效率和可持续性是评价二氧化碳电还原技术是否具有工业应用前景的主要指标.在碱性或中性电解液中进行二氧化碳电还原,由于部分二氧化碳在阴极转化为碳酸盐,导致碳利用效率降低.碱性电解液和中性电解液还分别存在电解液再生过程耗能巨大和溶液电阻较高等问题.这些因素导致使用碱性和中性电解液的二氧化碳电还原技术能量转化效率低下.最近,酸性条件下二氧化碳电还原技术有望提高碳利用效率和能量利用效率,成为研究热点.然而,在酸性条件下提升二氧化碳还原选择性具有挑战.前期研究已发展了多种策略以抑制酸性条件下的氢离子还原反应并促进二氧化碳还原反应,但研究者对于酸性条件下的阳离子效应以及局域pH效应等基础科学问题认识尚不一致.此外,气体扩散电极内的碳酸氢盐盐析问题仍限制着酸性条件下二氧化碳还原电解系统的可持续性.因此,亟需对促进酸性条件下二氧化碳电还原的不同策略及可能机制进行总结,并探讨进一步提升电解系统可持续性的潜在路径.本文首先概述了酸性条件下二氧化碳电还原技术的提出及发展历程,对比了碱性、中性和酸性电解液中... 相似文献
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近年来, 二氧化碳过量排放所引发的全球变暖等气候问题引起了全世界的广泛关注, 碳减排已成为人类社会可持续发展面临的共同挑战. 利用电化学方法将二氧化碳转化为高附加值化学品是实现碳减排和二氧化碳高附加值利用的理想途径之一, 但仍面临能耗高、 二氧化碳转化率低、 产物选择性差和难分离等问题. 本文以电还原二氧化碳制草酸为例, 从反应机理、 催化剂、 电解液、 催化电极及反应器等方面介绍该反应的研究进展, 对当前二氧化碳电还原制草酸存在的关键问题进行了分析, 并对其未来研究方向进行了展望. 相似文献
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大规模化石燃料的使用排放了大量的二氧化碳(CO2),导致环境中二氧化碳的含量急剧增加. 为了降低大气中二氧化碳的含量,以电催化的方法将二氧化碳转化为有用的化工原料和燃料是解决能源和环境问题的重要途径. 本文主要利用氧化还原刻蚀法,在铜表面形成复合纳米结构,用于二氧化碳的电催化还原反应研究. 首先,作者通过一定浓度的三氯化铁(FeCl3)溶液与铜片的氧化还原反应,在刻蚀铜表面时形成具有立方体结构的氯化亚铜纳米材料,用于二氧化碳的电催化还原反应. 为了研究反应时间对催化性能的影响,作者通过改变反应时间(1、2、3和4 h)合成了不同结构的铜基催化剂. 研究发现,在反应3 h后,Cu-3h催化剂对二氧化碳的电催化还原具有较小的起始电压(-0.3 V vs. RHE)和较大的电流密度值,表现出了较强的还原能力. 经检测,所得到主要还原产物为一氧化碳(CO)和甲烷(CH4). 在-0.6 V时,二氧化碳催化还原的法拉第效率可达到60%,表明以氧化还原法刻蚀铜表面具有较好的改善二氧化碳电催化还原的能力. 相似文献
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利用电催化技术将CO2转化为小分子燃料或高值化学品是实现原子经济、构建人工碳循环的绿色能源技术之一。电催化还原CO2 (ECR)的反应条件温和、产物多样(C1、C2和C2+),有极大的发展潜力。然而,ECR技术面临一些需要解决的挑战性问题,包括电极过电势高、C2及C2+产物选择性低、伴随析氢反应等。解决这些问题的关键在于创制低成本、高性能电催化剂。近年来,石墨烯基电催化剂的研究成为ECR领域的热点之一,原因包括:1)在电化学环境中稳定性好;2)表面原子、电子结构可调,进而实现材料催化活性的调控;3)维度可调,易暴露较大的比表面积和形成层次孔结构;4)耦合石墨烯的高导电性与特定材料的高活性,可协同提升ECR催化性能。本文评述了石墨烯基材料在ECR中的研究进展,详述了石墨烯基电催化剂的构筑方法,探讨并梳理了石墨烯的点/线缺陷、表面官能团、掺杂原子构型、金属单原子种类、材料表界面性质等与ECR性能之间的本征构效关系。最后展望了石墨烯基催化剂在ECR领域中的挑战和未来发展。 相似文献
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High Selectivity for Ethylene from Carbon Dioxide Reduction over Copper Nanocube Electrocatalysts
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Dr. F. Sloan Roberts Dr. Kendra P. Kuhl Prof. Anders Nilsson 《Angewandte Chemie (International ed. in English)》2015,54(17):5179-5182
Nanostructured surfaces have been shown to greatly enhance the activity and selectivity of many different catalysts. Here we report a nanostructured copper surface that gives high selectivity for ethylene formation from electrocatalytic CO2 reduction. The nanostructured copper is easily formed in situ during the CO2 reduction reaction, and scanning electron microscopy (SEM) shows the surface to be dominated by cubic structures. Using online electrochemical mass spectrometry (OLEMS), the onset potentials and relative selectivity toward the volatile products (ethylene and methane) were measured for several different copper surfaces and single crystals, relating the cubic shape of the copper surface to the greatly enhanced ethylene selectivity. The ability of the cubic nanostructure to so strongly favor multicarbon product formation from CO2 reduction, and in particular ethylene over methane, is unique to this surface and is an important step toward developing a catalyst that has exclusive selectivity for multicarbon products. 相似文献
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Dr. Chunjun Chen Prof. Dr. Xiaofu Sun Xupeng Yan Yahui Wu Prof. Dr. Huizhen Liu Dr. Qinggong Zhu Bernard Baffour Asare Bediako Prof. Dr. Buxing Han 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(27):11216-11222
Electroreduction of CO2 to CO powered by renewable electricity is a possible alternative to synthesizing CO from fossil fuel. However, it is very hard to achieve high current density at high faradaic efficiency (FE). Here, the first use of N,P-co-doped carbon aerogels (NPCA) to boost CO2 reduction to CO is presented. The FE of CO could reach 99.1 % with a partial current density of −143.6 mA cm−2, which is one of the highest current densities to date. NPCA has higher electrochemical active area and overall electronic conductivity than that of N- or P-doped carbon aerogels, which favors electron transfer from CO2 to its radical anion or other key intermediates. By control experiments and theoretical calculations, it is found that the pyridinic N was very active for CO2 reduction to CO, and co-doping of P with N hinder the hydrogen evolution reaction (HER) significantly, and thus the both current density and FE are very high. 相似文献
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Prof. Zhenyu Sun Dr. Neetu Talreja Hengcong Tao Prof. John Texter Prof. Martin Muhler Prof. Jennifer Strunk Prof. Jianfeng Chen 《Angewandte Chemie (International ed. in English)》2018,57(26):7610-7627
The transformation of CO2 into fuels and chemicals by photocatalysis is a promising strategy to provide a long‐term solution to mitigating global warming and energy‐supply problems. Achievements in photocatalysis during the last decade have sparked increased interest in using sunlight to reduce CO2. Traditional semiconductors used in photocatalysis (e.g. TiO2) are not suitable for use in natural sunlight and their performance is not sufficient even under UV irradiation. Some two‐dimensional (2D) materials have recently been designed for the catalytic reduction of CO2. These materials still require significant modification, which is a challenge when designing a photocatalytic process. An overarching aim of this Review is to summarize the literature on the photocatalytic conversion of CO2 by various 2D materials in the liquid phase, with special attention given to the development of novel 2D photocatalyst materials to provide a basis for improved materials. 相似文献
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Perfluorinated Covalent Triazine Framework Derived Hybrids for the Highly Selective Electroconversion of Carbon Dioxide into Methane
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Yuanshuang Wang Junxiang Chen Genxiang Wang Yan Li Prof. Dr. Zhenhai Wen 《Angewandte Chemie (International ed. in English)》2018,57(40):13120-13124
Developing cost‐effective electrocatalysts for high‐selectivity CO2 electroreduction remains challenging. We herein report a perfluorinated covalent triazine framework (CTF) electrocatalyst that displays very high selectivity in the electroreduction of CO2 to CH4 with a faradaic efficiency of 99.3 % in aqueous electrolyte. Systematic characterization and electrochemical studies, in combination with density functional theory calculations, demonstrate that the presence of both nitrogen and fluorine in the CTF provides a unique pathway that is inaccessible with the individual components for CO2 electroreduction. 相似文献
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Chunjun Chen Xiaofu Sun Xupeng Yan Yahui Wu Huizhen Liu Qinggong Zhu Bernard Baffour Asare Bediako Buxing Han 《Angewandte Chemie (International ed. in English)》2020,59(27):11123-11129
Electroreduction of CO2 to CO powered by renewable electricity is a possible alternative to synthesizing CO from fossil fuel. However, it is very hard to achieve high current density at high faradaic efficiency (FE). Here, the first use of N,P‐co‐doped carbon aerogels (NPCA) to boost CO2 reduction to CO is presented. The FE of CO could reach 99.1 % with a partial current density of ?143.6 mA cm?2, which is one of the highest current densities to date. NPCA has higher electrochemical active area and overall electronic conductivity than that of N‐ or P‐doped carbon aerogels, which favors electron transfer from CO2 to its radical anion or other key intermediates. By control experiments and theoretical calculations, it is found that the pyridinic N was very active for CO2 reduction to CO, and co‐doping of P with N hinder the hydrogen evolution reaction (HER) significantly, and thus the both current density and FE are very high. 相似文献
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Kirill V. Kholin Mikhail N. Khrizanforov Vasily M. Babaev Guliya R. Nizameeva Salima T. Minzanova Marsil K. Kadirov Yulia H. Budnikova 《Molecules (Basel, Switzerland)》2021,26(18)
A selective noble-metal-free molecular catalyst has emerged as a fruitful approach in the quest for designing efficient and stable catalytic materials for CO2 reduction. In this work, we report that a sodium pectate complex of copper (PG-NaCu) proved to be highly active in the electrocatalytic conversion of CO2 to CH4 in water. Stability and selectivity of conversion of CO2 to CH4 as a product at a glassy carbon electrode were discovered. The copper complex PG-NaCu was synthesized and characterized by physicochemical methods. The electrochemical CO2 reduction reaction (CO2RR) proceeds at −1.5 V vs. Ag/AgCl at ~10 mA/cm2 current densities in the presence of the catalyst. The current density decreases by less than 20% within 12 h of electrolysis (the main decrease occurs in the first 3 h of electrolysis in the presence of CO2). This copper pectate complex (PG-NaCu) combines the advantages of heterogeneous and homogeneous catalysts, the stability of heterogeneous solid materials and the performance (high activity and selectivity) of molecular catalysts. 相似文献
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Selective and Efficient Reduction of Carbon Dioxide to Carbon Monoxide on Oxide‐Derived Nanostructured Silver Electrocatalysts
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Ming Ma Bartek J. Trześniewski Jie Xie Dr. Wilson A. Smith 《Angewandte Chemie (International ed. in English)》2016,55(33):9748-9752
In this work, the selective electrocatalytic reduction of carbon dioxide to carbon monoxide on oxide‐derived silver electrocatalysts is presented. By a simple synthesis technique, the overall high faradaic efficiency for CO production on the oxide‐derived Ag was shifted by more than 400 mV towards a lower overpotential compared to that of untreated Ag. Notably, the Ag resulting from Ag oxide is capable of electrochemically reducing CO2 to CO with approximately 80 % catalytic selectivity at a moderate overpotential of 0.49 V, which is much higher than that (ca. 4 %) of untreated Ag under identical conditions. Electrokinetic studies show that the improved catalytic activity is ascribed to the enhanced stabilization of COOH. intermediate. Furthermore, highly nanostructured Ag is likely able to create a high local pH near the catalyst surface, which may also facilitate the catalytic activity for the reduction of CO2 with suppressed H2 evolution. 相似文献